The ATR kinase has a role in mitosis to promote chromosome segregation During mitosis, each duplicated chromosome must be accurately attached to the microtubule spindle, which pulls the chromosomes to opposite poles of the cell, where they are segregated to daughter cells. A number of mitotic kinases orchestrate mitosis to ensure accurate segregation, including cyclin-dependent kinase 1 (CDK1), the Polo-like kinases, and the Aurora kinases (1). The kinase ATR (ataxia telangiectasia and Rad3-related), which is involved in DNA damage responses during interphase of the cell cycle, has also been shown to prevent chromosome segregation errors (2). However, this role of ATR was presumed to be an indirect effect. On page 108 of this issue, Kabeche et al. (3) unveil a mitosis-specific ATR activity that ensures proper chromosome segregation and that this activity is dependent on a specific three-stranded nucleic acid structure known as an R loop.

中文翻译：

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新的有丝分裂活动成为焦点

ATR 激酶在有丝分裂中具有促进染色体分离的作用 在有丝分裂期间，每条复制的染色体都必须准确地附着在微管纺锤体上，微管纺锤体将染色体拉到细胞的两极，在那里它们被分离到子细胞。许多有丝分裂激酶协调有丝分裂以确保准确分离，包括细胞周期蛋白依赖性激酶 1 (CDK1)、Polo 样激酶和 Aurora 激酶 (1)。激酶 ATR（共济失调毛细血管扩张症和 Rad3 相关）在细胞周期的中间阶段参与 DNA 损伤反应，也已被证明可以防止染色体分离错误 (2)。然而，ATR 的这种作用被认为是一种间接影响。在本期第 108 页，Kabeche 等人。